Background

With the debut of FSRS-5 in Anki 24.11, there's now considerable controversy surrounding whether FSRS should control short-term intervals. Additionally, some inaccurate information about short-term memory is spreading.

• Anki 24.11: one of the biggest updates ever : r/Anki
• What is the benefit of FSRS taking over re-learning steps? : r/Anki
• What is your experience with FSRS learning steps? : r/Anki
• (Re)learning steps : FSRS5 VS FSRS Helper : r/Anki
• STOP Leaving Your Learning Steps Blank : r/Anki

Therefore, I feel it necessary to provide some clarification.

Fact

• In Anki 24.11, when FSRS is enabled and (re)learning steps are left blank, FSRS can control the (re)learning steps when it deems necessary (when the next interval < 12h).
• FSRS-5 was not initially designed to model short-term memory. Its primary focus was on considering the impact of short-term reviews on long-term memory.
• During the optimization of FSRS-5 parameters, short-term review results were not used as labels in supervised learning. Using a next token prediction analogy, short-term reviews appeared only in the input/context tokens, not in the next tokens.
• Benchmarks show that considering short-term reviews improves long-term memory prediction accuracy. However, this doesn't necessarily mean FSRS-5 can accurately predict short-term memory.
• Recent experiments involving short-term review results as optimization labels led to a significant increase in FSRS prediction errors and overly conservative long-term memory predictions. This suggests that long-term and short-term memory patterns may differ, and using a single model to predict both may not be ideal.
• Short-term reviews have a significant impact on short-term memory. But it’s too complicate to model.

FAQs

Most of my answers are based on my open-source research: open-spaced-repetition/short-term-memory-research

What inspired the module considering same-day reviews in FSRS-5?

The inspiration came from my research on short-term review data: